Virtually all caudates will accept regular Lumbricus earthworms, the kind you find outdoors in dirt, or buy labeled as Canadian nightcrawlers. When it comes to compost worms, things get a bit more complicated.
There are 2 species of compost worms that are commonly grown in a tub or bin: (1) "red wigglers" = "tiger worms" (small adults about 2-3 inches, with highly defined red rings), and (2) "european nightcrawlers" = Dedrobena (larger adults, about 3-5 inches, slightly less red in color). Both types of compost worms have SOME of the nasty smell that causes SOME newts/axolotls to reject them. In terms of nutrition and safety, all of them are good.
I grow the larger worms (Dendobena), and I have no difficulty getting my newts & axies to eat them. I never cut them up, I only serve them whole. For my smaller animals, I pick out smaller (juvenile) worms from the tub. All of them are gobbled up, no problem.
The reasons that the funky smell can be a problem are: (1) if you use the smaller red wiggler worms, which have a stronger smell (2) you buy compost worms that have been raised in manure, or (3) you cut the worms into pieces, releasing the internal smell.
I hope this makes sense. I would encourage you to "grow your own". Once they get established, it's an endless supply of free food, and a good way to compost kitchen scraps. The further complication is how to be sure that the starter worms you buy are really Dendobena, not the smaller red wigglers.